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Discussion Starter · #1 ·
My car is a 65 GTO 389 tri power which does not have hardened valves. Wanted to know what octane gasoline or combination of gasoline plus additives other individuals with similar cars use, which includes ethanol free gasoline? Ethanol free gasoline in my area is 90 octane, would you recommend using an additive or mix a higher leaded octane gasoline with the ethanol free to keep the engine running at its best.
 

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My 67 400 with the advertised 10.75:1 compression heads (670's) liked nothing below 91 octane non-ethanal back in the day and I used a lead substitute with almost all fill-ups. I don't recall it pinging much on the lower octanes, but it sure would diesel when you turned it off, or tried to. I would often have to leave it in gear and turn the key off to keep it from running on. Do you know your compression ratio or, at least, your head castings...that will make a difference in accuracy of the answers you get.

My opinion on lead substitute is that it is definitely required for nonhardened valve seats with heavy duty applications like towing. So, I concluded that driving the GTO like it was meant to be driven was probably up there with towing and would appreciate the lead substitute.
 

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67 GTO
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Like already said.... I would not worry so much about the Lead , but the octane.....
I like get as close to 100 octane as I can.....

Usually 10 gallons of 93 mixed with 5 gallons of VP110 = 15gallons of about 100 octane with some lead from the VP110

or

I use 10 gallons of 93 mixed with a quart of VP Octanium additive - which gives me 10gallons at about 100 octane

Buy VP Octane Booster - Octanium® | VP Racing Fuels
 

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No worry about lead additives in regards to the valve seats. Use enough octane to keep the engine from detonation. One of the octane boosters that actually works is Octane Supreme 130, which uses tetraethyl lead as the boost agent. Not cheap, but it does work.
 

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Discussion Starter · #6 ·
It sounds like there are numerous options for increasing the octane, thanks for the suggestions. One additional question, which would you prefer to add an octane booster to 90 octane ethanol free or 93 octane unleaded? My engine is a 389 WS with stock heads, I'm estimating that compression is around 10:75 to 11.
 

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this
Like already said.... I would not worry so much about the Lead , but the octane.....
I like get as close to 100 octane as I can.....

Usually 10 gallons of 93 mixed with 5 gallons of VP110 = 15gallons of about 100 octane with some lead from the VP110

or

I use 10 gallons of 93 mixed with a quart of VP Octanium additive - which gives me 10gallons at about 100 octane

Buy VP Octane Booster - Octanium® | VP Racing Fuels
 

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67 GTO
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Is it real lead too?

They do have 2 version - one for cars needing Lead and the other for cars NOT needing lead

The one for engines needing Lead....... still does NOT have lead in it..... but must have some other additive to make up for it. I am not concerned with the Lead as much as I want octane.....

I picked up the Octanium at the VP tent at Maple Grove Raceway for $15/can - that is 1/2 the cost of the Octane Supreme and seems to be doing the same job
 

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Like already said.... I would not worry so much about the Lead , but the octane.....
I like get as close to 100 octane as I can.....

Usually 10 gallons of 93 mixed with 5 gallons of VP110 = 15gallons of about 100 octane with some lead from the VP110

or

I use 10 gallons of 93 mixed with a quart of VP Octanium additive - which gives me 10gallons at about 100 octane

Buy VP Octane Booster - Octanium® | VP Racing Fuels
Around here, 100 octane unleaded from the pump (but has ethanol so could add Lucas ethanol additive $10) is $10/gallon. $210/tank, 100 octane.

And guess what, the 110 octane leaded from the pump is... $10/gallon. $200/tank, 110 octane.

I could start mixing 5 gallons of 110 leaded with 15 gallons of 93 ethanol-free at $5/gallon to drop overall price per tank. $125/tank, 97.25 octane.

Or I could buy 20 gallons of $5 93 octane ethanol-free and add a $25 quart can of VP Octanium ("adds 8 points")? $125/tank, 101 octane?

Which approach do you like better?
 

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1972 Lemans GTO w/ 1970 455HO engine and a 4 speed.
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Does this really work? I have 1970 455ho motor with 10.5 to 1 compression. Local stations have 91 octane and race leaded ethanol free 110 but the hose is pinned down so you can’t fill a car. Kind of a pain in the butt so will the Octanium be safe if I get to say 99 with the additive or is this snake oil??
 

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Around here, 100 octane unleaded from the pump (but has ethanol so could add Lucas ethanol additive $10) is $10/gallon. $210/tank, 100 octane.

And guess what, the 110 octane leaded from the pump is... $10/gallon. $200/tank, 110 octane.

I could start mixing 5 gallons of 110 leaded with 15 gallons of 93 ethanol-free at $5/gallon to drop overall price per tank. $125/tank, 97.25 octane.

Or I could buy 20 gallons of $5 93 octane ethanol-free and add a $25 quart can of VP Octanium ("adds 8 points")? $125/tank, 101 octane?

Which approach do you like better?
And this is why we build an engine with lowered compression. 20 gallons of $3.39 89 octane = $67.80 and I can enjoy driving it long distances.............and back instead of on the back of a trailer.

So if you got 12 miles per gallon, you can drive 240 miles, or 3.4 hours at 70 MPH (that's a show that is 120 miles away and back) for $125.00, or much less if you plan on cruising around with the car once at an event. If I went to a car show 4 hours away, well, that's close to half my take-home pay - Ouch! Why own it if I can't drive it much or be limited to how far away I can drive my car. Certainly won't be any Route 66 cross country runs at that price unless I hit the lottery or stand at an exit ramp seeking money for gas to continue my journey. (y)
 
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